It was hard to keep track of Tyler Roy’s testimony at the jailhouse beating trial on Tuesday because he kept changing his story.

It didn’t help that he couldn’t remember what he said under oath a day earlier.

The former Innes Road jail guard was called as a Crown witness to testify against a fellow former guard — John Barbro — who’s on trial for the alleged Oct. 23, 2010 boot-stomping of a handcuffed and shackled inmate who lay pinned to the floor by a mob of guards.

On Monday, Roy told court that he radioed for backup after inmate Jean Paul Rheaume became unruly because he wanted to go for a walk after being locked up all day in segregation cell No. 11 on One Wing.

Roy gave elaborate testimony Monday detailing why he called for backup. But a day later, on Tuesday, Roy told a different story, testifying that he never actually called for backup.

He changed his story under cross-examination by Michael Edelson, who is defending Barbro.

Roy changed his story to adopt the same version of events he gave to internal jail investigators in 2011, saying he never called for fellow guards to help him and partner Melissa Schell, who is still a guard at the Ottawa-Carleton Detention Centre.

Edelson suggested the reason Roy didn’t actually call for backup was because he didn’t want any witnesses around as he lay a beating on the inmate, who was serving 30 days for break and enter.

“You created the whole story out of thin air to justify your use of force. It was all total nonsense,” Edelson declared to a packed courtroom.

The victim, who had not yet been called to testify, told the internal jail investigators it was Schell and Roy who dragged him out of his cell, threw him on the floor and started kicking him in the head.

“I got thrown in the corner and right away kicked in the head with boots, and it didn’t stop,” Rheaume told jailhouse investigators.

Roy denies roughing up the inmate.

During the intense cross-examination Tuesday, Roy said he was confused, nervous and had a lousy memory when it came to recalling the bloody events of four years ago. Edelson said Roy suffered from selective amnesia.

Roy testified that he called for Rheaume’s cell to be opened and then closed so he and a fellow guard could collect meal trays.

But court heard that the jailhouse computer logs of cell door openings and closings showed that Rheaume’s cell door was opened a second time, some 10 seconds later.

Roy said he couldn’t recall that, and when Edelson told him that it had to be reopened because the guard and his partner had accidentally locked themselves into Rheaume’s cell when they started roughing up the inmate, Roy denied it.

An internal investigation at the jail concluded that at least one guard accidentally trapped themselves inside the cell with Rheaume and a cellmate.

Under oath, Roy denied that. The ex-guard also testified that he couldn’t remember the presence of other guards at the scene, including the accused.

Roy also denied meeting with colleagues to get their stories straight.

Schell testified earlier that she left key details out of her report about the beating to protect herself and the accused, Barbro. Neither Schell nor Roy noted any of Rheaume’s injuries in their occurrence reports.

Schell has also insisted she never set foot inside the Rheaume’s cell and denied dragging him out to beat him.

Her testimony is at odds with evidence from two other witnesses, among them the alleged victim. They say she and Roy were not only inside the cell, but got themselves accidentally locked inside of it with the two inmates.